[Startup Tracing] Remove |is_recording_| in devtool tracing_handler

content/browser/devtools/protocol/tracing_handler.cc

Index: content/browser/devtools/protocol/tracing_handler.cc
diff --git a/content/browser/devtools/protocol/tracing_handler.cc b/content/browser/devtools/protocol/tracing_handler.cc
index 4ba32ed9819861c595ac92675a75f1e976a65479..ead61d828d1b9bfc8bd47c1e214ecd712764bf13 100644
--- a/content/browser/devtools/protocol/tracing_handler.cc
+++ b/content/browser/devtools/protocol/tracing_handler.cc
@@ -47,7 +47,6 @@ class DevToolsTraceSinkProxy : public TracingController::TraceDataSink {
 
 TracingHandler::TracingHandler(TracingHandler::Target target)
     : target_(target),
-      is_recording_(false),
       weak_factory_(this) {
 }
 
@@ -59,7 +58,7 @@ void TracingHandler::SetClient(scoped_ptr<Client> client) {
 }
 
 void TracingHandler::Detached() {
-  if (is_recording_)
+  if (IsRecording())
     DisableRecording(true);
 }
 
@@ -83,10 +82,9 @@ Response TracingHandler::Start(DevToolsCommandId command_id,
                                const std::string* categories,
                                const std::string* options,
                                const double* buffer_usage_reporting_interval) {
-  if (is_recording_)
+  if (IsRecording())
     return Response::InternalError("Tracing is already started");
 
-  is_recording_ = true;
   base::trace_event::TraceConfig trace_config(
       categories ? *categories : std::string(),
       options ? *options : std::string());
@@ -111,7 +109,7 @@ Response TracingHandler::Start(DevToolsCommandId command_id,
 }
 
 Response TracingHandler::End(DevToolsCommandId command_id) {
-  if (!is_recording_)
+  if (!IsRecording())
     return Response::InternalError("Tracing is not started");
 
   DisableRecording(false);
@@ -171,12 +169,15 @@ void TracingHandler::SetupTimer(double usage_reporting_interval) {
 }
 
 void TracingHandler::DisableRecording(bool abort) {
-  is_recording_ = false;
   buffer_usage_poll_timer_.reset();
   TracingController::GetInstance()->DisableRecording(
       abort ? nullptr : new DevToolsTraceSinkProxy(weak_factory_.GetWeakPtr()));
 }
 
+bool TracingHandler::IsRecording() {
+  return TracingController::GetInstance()->IsRecording();
+}
+
 }  // namespace tracing
 }  // namespace devtools
 }  // namespace content